1. Field of the Disclosure
The present disclosure sets forth a thrombectomy catheter, but more specifically relates to a rheolytic thrombectomy catheter with a self-inflating distal balloon, alternately referred to herein as the “rheolytic thrombectomy catheter” for purposes of brevity. The terms used herein are not intended to be limited to any particular narrow interpretation unless clearly stated otherwise in this document.
2. Description of the Prior Art
Prior art and its comparison to the devices of the present disclosure are partially set forth herein. Flow cessation of prior art devices to minimize hemolysis and for other reasons has been accomplished via a balloon on a proximally or distally placed guide catheter or by way of proprietary occlusion guidewire technology, such as, but not limited to, the use of balloons on guidewires. Neither of these methods places the occlusive balloon directly and dynamically on the catheter. In general, placing an occlusion device proximally at the guide catheter or the use of a distal protection device will result in the need to upsize the interventional sheath or will result in a substantial increase in the cost of the procedure, or both. The devices of the present disclosure permit the use of the same sized introducer sheath with much less dramatic increase in costs to the physician.
The present disclosure describes a rheolytic thrombectomy catheter utilizing the concept of a continuously formed inflatable and expandable balloon which is continuously formed of the same material as the catheter tube (exhaust tube) and which is automatically inflated by an internal pressurization caused by high velocity fluid jet flows and the like. Such a concept can also be applied to other thrombectomy catheters and systems, such as, but not limited to, all AngioJet® catheters including rapid exchange catheters, over-the-wire catheters, and catheters which are pressurized by a fluid flow source. A self-inflating balloon is located distal to an inflow gap or orifice and distal to a fluid jet emanator. This self-inflating balloon is inflated and expanded by the utilization of internal operating forces consisting of forwardly directed high velocity fluid jet streams and entrained thrombus particulate therein. The self-inflating balloon is aligned within the walls of the blood vessel to isolate sections of the blood vessel distal and proximal to the inflated balloon in order to prevent flow of thrombus particulate, fluids and the like, distal to the self-inflating balloon and to provide a stagnant nonflow region proximal to the self-inflating balloon.
Vessel safety is improved and enhanced by use of the devices of the present disclosure. In previously designed cross flow thrombectomy catheters, vessel damage is primarily inflicted by the inflow orifices. The vessel wall can be sucked in by the negative pressures at the inflow orifices to the point that the internal high velocity jet streams can damage the vessel wall. In fact, merely moving the catheter while the inflow orifices have been sucked onto the vessel wall is a likely mechanism for vessel damage from cross stream catheters. Vessel damage increases with the size of the inflow orifices and with the proximity of the high velocity fluid jet stream origin to the inlet orifice. For the devices of the present disclosure, an inlet gap (inlet orifice) is positionally located away from the vessel wall by the centering action of the self-inflating balloon. Additionally, inflation of the self-inflating balloon ensures centering of the device in the vessel in order that treatment may be provided equally in all circumferential directions. Furthermore, the centering feature enables a greater and more uniform delivery of drugs into tougher mural thrombus. This design enables a more effective and greater removal of tougher and more organized thrombus.